1. Soil erosion by water occurs in stages as the volume and velocity of runoff increase.
2. Splash erosion: The first stage, where raindrops strike bare soil, dislodging soil particles.
3. Sheet erosion: Occurs as runoff flows in a thin layer (sheet) over the soil surface, removing a uniform layer of topsoil.
4. Rill erosion: As runoff concentrates, it begins to cut small channels (rills) into the soil surface.
5. Gully erosion: Rills deepen and widen, merging to form larger channels called gullies, which can significantly damage the land.
6. Therefore, the correct order of the processes of soil erosion is Splash erosion, Sheet erosion, Rill erosion, Gully erosion.